Hinges for furniture have long been on the market, comprising an arm able to be fixed to a fixed element of the furniture and a box-shaped element able to be fixed to a door of the furniture, a first and a second rocker arm which operatively mutually connect the box-shaped body and the arm, and which define with them an articulated quadrilateral.
Such hinges usually have springs of various kinds for creating a retraction force by closing and/or opening the doors, on which they are applied. In such hinges the presence is desirable of deceleration devices of the movement of the doors caused by the elastic rotation of such springs. Such deceleration devices have the aim mainly to avoid the noises due to hard impacts against the body of the furniture during the closing of the doors.
Deceleration devices are known, based on the use of viscous means that are interposed among mutually moving parts.
In such case the efficiency of the deceleration device heavily depends on the ambient temperature in which the viscous means is used, being its viscosity clearly dependent from this.
For example, the use of a high viscosity means can be counterproductive if the ambient temperature is excessively lowered, as this can cause the blocking of the hinge, whereas the use of a low viscosity means can be inefficient if the ambient temperature is excessively raised (for example if on the hinge in question a beam of light is focused, produced by the artificial lighting present in an apartment). Deceleration systems have been provided which have a combined effect of a mechanical and viscous kind for the deceleration of the rotation of the hinge.
In particular reference is made to deceleration systems in which a plastic container filled with viscous fluid houses a friction disc rotatable against a sliding surface. A movable cursor due to the rotation of the hinge supports a drive element able to transform the translation of the cursor in a rotation of the friction disc.
In such systems the prevailing deceleration effect is in any case of a viscous kind and the above discussed drawbacks are therefore solved only marginally.
Such deceleration systems can also lament the drawback of having a limited efficiency and structural resistance together with a short useful life due to the high stress and wear to which their constituent parts are subjected.